Improvement in blind-stops



W. A. CLARK.

Blind-Stop.

Patented Feb.. 23, I875.

No.160,05l.

THE GRAPHIC lib-PHOTOrLITH-398z4l PARK PLACE,N-Y.

WILLIAM A. CLARK, OF NEW HAVEN, CONNECTICUT.

IMPROVEMENT IN BLIND-STOPS.

Specification forming part of Letters Patent No. 160,051, dated February 23, 1875; application filed January 4, 1875.

CASE B.

To all whom it may concern Be it known that I, WILLIAM A. CLARK, of New Haven, in the county of New Haven and State of Connecticut, have invented certain Improvements in Blind Stops, of which the following is a specification My invention relates to blind-stops and it consists of a metal plate secured to one of the slats of a blind, with a spring-bolt arranged to hat-e its end bear against the side of the plate so as to hold the slats in position by friction, the bolt also serving to lock the slats fast when closed, as hereinafter more fully ex plained.

Figure 1 is a front "iew of a portion of a blind with my stop attached. Fig. 2 is a vertical section of the same on the line a; so of Fig. 1, and Fig. 3 a view of the plate modified in form.

To construct my stop I provide a small segmental plate of metal, D, which may be most conveniently cut out of sheet metal, of the form shown in Fig. 2, it being provided at each end with an ear, 0, bent at a right angle to the body, and having a hole in them to receive a small screw or tack by which the plate D is fastened to the inner face of a slat, B, as represented 1n Figs. 1 and 2. If desired, the upper ear 0 may be so constructed as to en gage with the staple that fastens the rod 0 to the slat, though this is not essential. I then provide a small bolt, E, which I mount on-a simple plate, l, and place on said bolt a spiral spring, f, in such a manner as to press the end of the bolt against the side of the plate D, thereby creating sufficient friction to hold the slats B at any angle desired.

In the plate D, near its lower end, I make a hole, n, as shown in Fig. 2, so that when the slats are closed the bolt E will enter this hole, and thus lock the slats fast, as represented in Fig. 1.

As the slats B are turned to a horizontal position, the weight of the rod (J acts upon them with a constantly increasing force, thus tending to make the slats turn automatically, if very loose, and requiring an increase of friction or force to hold them. To compensate for this, I place the plate D with its upper end inclined slightly toward the bolt, so that as the slats are opened the plate will tend to crowd back the bolt f as it moves, and thereby increase the friction of the bolt and plate.

Instead of inclining the plate, as described, it may be slightly bent at its center, as represented in Fig. 3, thus forming a double incline on its face, against which the bolt f bears. When thus constructed it will be seen that the friction will increase until the slats are turned to a horizontal position, after which it will decrease in a corresponding manner. While this modification renders the device more perfect, still the plan first described is found sutficient for all practical purposes, more especially as it is seldom necessary to turn the slats beyond a horizontal position.

The device is very simple and efiicient, and can be operated by one hand, which is a great consideration when a person is reading or otherwise employed.

I am aware that a spring-bolt has before been used for a similar purpose, but I am not aware that it has ever been used in connection with a friction-plate so constructed or arranged as to increase the friction as the slats were turned to Witnesses:

J OHN N. AUSTIN, GEORGE L. FINNEY. 

